Sneak Peak at Response Files (.rsp)

The Visual Studio has evolved so much that anyone hardly uses the CSC.exe tool and command line switches any longer. But there could be days when you are forced to opt for CSC.exe and the biggest woe is the huge list of switches/parameters that you need to associate each time you want to compile using csc.exe.

The response files (*.rsp) provides a cleaner way to find a solution for this problem, inevitably also taking caring of accidentally missing parameters. Response files is plain text files which contains a set of switches you would like to apply to your compilation command. Let’s consider the example.

csc.exe /out:jia.exe /t:exe program.cs

We have opted for a simple example. In real life, you could be referring to a bag full of dependencies, which you would have to include using the /r switch. But for sake of example, we will stick to simple example mentioned above. We will now write out response file to include the /out and /t switches.

/out:jia.exe
/t:exe

We will name it as “app.rsp”. Now, to compile our cs file, we would need to specify the rsp file using the @ prefix.

csc.exe @app.rsp program.cs

The .Net framework uses a similar approach internally by employing a global response file (csc.rsp). This is the reason we could compile the source files even when skip referencing commonly used dlls in command.